The Circulatory SystemAKA The Cardiovascular System

AKA The Body’s “Transport System”

• Consists of the heart, blood and blood vessels.

The components are . . .

1. Heart

2. Blood vessels

3. Blood

Used to 1. carry needed substances to

cells and 2. carry waste products away

from cells. And your blood 3. contains cells to fight

disease.

Needed Substances:oxygenglucose

Waste Products:Carbon Dioxide

Disease Fighters:white blood cells

The Heart: 2 pumps; 4 sections

• The size of your fist.• Located in the center of your

chest.• With each beat, blood is being

pushed through the blood vessels.

Identify the blood vessels in the heart.

1. Vena Cava 2. Aorta3. Pulmonary

Artery

4. Pulmonary Vein

Flow of blood:• Oxygen depleted blood

• Oxygenated blood

• Vena cava• Right atrium• Right ventricle• Pulmonary Artery (Arteries Away!)• To lungs• In the lungs: CO2 is exchanged for O2.

Oxygenated blood goes back to the heart.• Pulmonary veins (veins IN)• Left atrium• Left ventricle• Aorta (largest artery)• To the body

This process keeps going in a circle…it’s

not called the Circulatory System for

nothing!

Blood Vessels:

Arteries: (Arteries Away!)carry blood __________ from the heart.Carries oxygen rich blood (1

exception=Pulmonary artery). Have thick elastic walls made of smooth muscle.

Each ventricle is attached to an artery.Arteries branch into capillaries.

Veins: (veins IN)

Carry blood in to the heart. Low pressure, Near skin surface. Thin walls. Oxygen poor (1 exception=Pulmonary vein)

Have valves to prevent backflow.

Capillaries

Microscopic. One cell thick. Only one blood cell through at a time.

Where all diffusion happens.

PARTS OF BLOOD

•45% OF BLOOD IS MADE OF CELLS; THE REST IS PLASMA.

PLASMA:

• Straw-colored, liquid part of blood. 10% are the dissolved materials that must travel via the blood, the other 90% is water. Carries most of the CO2 in the blood.

RED BLOOD CELLS

• Take up oxygen in the lungs and deliver it to cells. Produced in the bone marrow. Thin, disk-shaped and flexible. Live for about 120 days.

HEMOGLOBIN:

• Iron-containing protein that gives blood its ability to carry oxygen. When hemoglobin combines with O2, blood turns bright red.

WHITE BLOOD CELLS

• Body’s disease fighters. There are fewer WBCs than RBCs. WBCs are bigger than RBCs. Can live for months or even years

PLATELETS

• Small pieces of cells help the blood to clot. They produce a protein called fibrin that weaves tiny fibers across a cut and traps blood cells.

• A scab is simply a dried blood clot.